Physician Specialty and Carotid Stenting Among Elderly Medicare Beneficiaries in the United States

Study Questions:

What is the current specialty composition of operators performing carotid stenting in the United States and the extent to which specialty of operator explains variation in its utilization and outcomes across different health care markets?


The investigators performed an observational analysis of fee-for-service Medicare beneficiaries 65 years or older undergoing carotid stenting between 2005 and 2007 in 306 hospital referral regions (HRRs). They first determined how frequently carotid stenting was performed by different specialists within each HRR and then used multivariable regression models to compare population-based utilization rates and 30-day outcomes for this procedure across HRRs based on the proportion performed by cardiologists, surgeons, radiologists, or a mix of specialists. Multivariable linear regression models were used to assess if rates of utilization and risk-standardized 30-day mortality differed between HRRs where most procedures were performed by cardiologists, relative to HRRs where most procedures were performed by surgeons or radiologists or mixed HRRs.


In 272 HRRs where at least 15 procedures were performed during the study period, the investigators identified 28,700 carotid stenting procedures performed by 2,588 operators. While cardiologists made up approximately one-third of these operators, they were responsible for 14,919 (52.0%) procedures. Significant differences were noted in the characteristics of patients treated by cardiologists compared with other specialties, including higher rates of invasive cardiac procedures and lower rates of acute stroke or transient ischemic attacks in the 180 days prior to carotid stenting. Population-based utilization rates were significantly higher in HRRs where cardiologists performed most procedures relative to HRRs where most were done by other specialists or a mix of specialists (p < 0.001). In contrast, risk-standardized outcomes did not differ across HRRs based on physician specialty.


The authors concluded that HRRs where cardiologists perform most procedures have higher population-based utilization rates with similar outcomes.


This study suggests that cardiologists in the United States play an important role in carotid stenting, and HRRs where cardiologists performed most carotid stenting had higher population-based utilization rates than other HRRs with similar outcomes. Additional studies are needed to better understand the specific nature of this relationship and whether multidisciplinary decision making by teams of specialists (similar to heart team approach) could optimize the use and appropriateness of this innovative technology.

Keywords: Stroke, Health Care Sector, Ischemic Attack, Transient, Fee-for-Service Plans, Cardiology, Medicare, United States

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